The invention relates to a drivetrain comprising a drive unit having an associated drive shaft, a transmission with at least one transmission input shaft and at least one driving wheel joined to an output shaft of the transmission as well as an automatic actuation friction clutch interposed between the drive unit and the transmission.
Systems of this type have long been included within the state of the art. Typically, the automatic actuation friction clutches are actuated, for example, via actuators that operate according to a hydraulic, pneumatic or electromechanical principle. Furthermore, hydraulic slave cylinders are known that are impinged by a master cylinder driven by an electric motor. In this context, actuators of this type effect an axial movement of appropriately configured actuating means, usually with a throwout bearing being interposed along the rotary axis of the drive shaft or the transmission input shaft and thereby acting in an axial direction on an axial operable energy storage mechanism, such as a cup spring, that axially braces a clutch plate having friction linings and joined in a rotationally fixed manner to the transmission input shaft against frictional engagement surfaces of the clutch plates that are joined in a rotationally fixed manner to the drive shaft of the drive unit. In this way a frictional connection is produced that transmits that torque of the drive unit, such as an internal combustion engine with a crankshaft, to the transmission input shaft. After associated conversion in the transmission, the transmitted torque drives the driving wheels via the transmission output shaft and a differential. The transmission here may be manual-shift or automatically actuated via actuators and having various gear ratios.
Especially in the transmission of torques in the clutch slip phase, i.e., when there is a speed differential between the drive shaft and the transmission input shaft, a so-called judder can occur as a result of component anomalies, axial vibrations of the drivetrain, lining properties and the like. This judder is manifested by virtue of the so-called stick-slip effect being expressed in a temporary clinging of the frictional lining of the clutch plate to the opposing frictional surface of the clutch pressure plate followed by a release of the stiction. As a result, so-called judder vibrations occur in the drivetrain, and for that matter in the entire vehicle, that negatively affect driving comfort and the service life of various components in the motor vehicle.